Disclosed is a semiconductor device which makes it easy to design a wiring pattern for a wiring substrate on which the semiconductor device is to be mounted. In manufacturing plural semiconductor devices for providing different amounts of output current, arrangements and numbers of leads to which semiconductor chips for power transistors of the semiconductor devices are to be electrically connected are changed according to output current requirements for the semiconductor devices, whereas arrangements and numbers of leads to which semiconductor chips for control circuits of the semiconductor devices are to be electrically connected are fixed to be common to the semiconductor devices. In this way, the probability of malfunction of control circuits (PWM circuits) of the semiconductor devices can be reduced, so that a semiconductor device which makes it easy to design a wiring pattern for a wiring substrate on which the semiconductor device is to be mounted can be provided.